Optional dependency on binary via package flags

[LaurentRDC]

This pull request is a continuation of #111 , but only for the binary package (and Binary instances).

I restricted to binary because this is what I use and could test quickly; happy to add more instances and flags if people are interested.

99% of this work was done by @dmcclean ; thank you!

[bjornbm]

Thanks @LaurentRDC! For the record, what “environment” (GHC, etc.) did you test in?

FYI I ran a build on LTS Haskell 20.24 (ghc-9.2.7) and tested with stack test --flag dimensional:binary --haddock --no-haddock-deps --bench. All completed fine and the haddocks showed the Binary instances.

[LaurentRDC]

I tested exclusively with GHC 9.10.1

[LaurentRDC]

For my next contribution, I'll set up Github Actions for multiple GHC versions ;)

[bjornbm]

Thanks @LaurentRDC!